Circuit-interrupter system



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.LLOYD J. HIBBARD, oFvE'As'T PITTSBURGH, PENNSYLVANIA, AssIeNon To` WnsTrNe- CIRCUIT-INTERRUBTER SYSTEM.

Annamaria @une f1.0, .192e ,Serial Nol .5.614,11-

invention ,relates @to circuitdnterrupter .systemszthat arejemployed .for controilllingthe how ofjcurrent from a gh-,tension'linefto la,traifisformer ,or l,( ither electrical apparatus and Particularly@ means-,fer protesting 0011s ...gaisteexcessvie `surges ef fmirreli there: through. c f My nrenten has fOff its ,Obiesfzthe Y,pro- .yision of incansfor ,protectingfthe endturns of coils, siich'as are employed in' transformers,y against voltage surges` induced "therein when Y breaking the circuit through the transformerhor other a paratus of which the coils ,form a. part, Lan (2) from ysurges of current incident to, Ithe* `olf ,the circuit .on a high wayefront. i f

`My ,inve'n'ion' ywill bst be understood by referring t l', the drawing; ,in :which f' x Figures l andi 2 are diagrammatic yiews of one ymeans :for practicing invention.

Ka pantograph ecurrent cgllector Qfcoactsto transmit enrsytee tfeforeisf ter'isilpplying K,an electric vehicle (not shown) I prot-'idel a maifn'vswitch 4 and auxiliary switches 5 and 6 for controlling the flow of current to the transformer 3, the switch 6 being normally open when the main switch 4 is closed.

In the position shown in lthe drawing, the circuit through the transformer is broken. When it is desired to yconnect the transformer 3 to the line 1, the switch 5 is first closed andthe switch 6 then opened.y A reactor 7, preferably of the air-core type, is

` thereby connected 1n the circuit to rprotect the transformer 3 against a voltage surge in the event that the switch is yclosed on a high wave front. The main switch 4 may then be closed,lthus short circuitingthe re-v actor `7.

- In breaking the circuit,the main switch 4 i i kis rst opened, followed by the closing of the switch (Sand the opening of the switch 5. A path for dissipating the energy whichl is stored in the transformer, if the circuit happens to be'broken at the peak point of a current wave, isy thereby provided across the end turns ofthe transformer 3 through i an auxiliary circuit 8 andthe desired number of turnsof the reactor 7. e y The switches may be of the oil-immersed type and to insure proper sequence of op-v eration, a cam operating ,device Y as `shown inngFig. 2,inaybeemployed, and for light duty a rotary drum typev switch would `be eifectiye yin producing the desired sequence.

`,In the'jalfioye saidffigure, the circuit inter'-y Asii-ablex because. `yiiithth'e reactor constantly.

under full load,excessiye'heatis deyelo ed inthereactor y'and lin )any metalfp'arts are adjacent thereto. m-y ,arrangei'neiia Hthe if desired '."protection vis' secured' `'iivitliout eXcessi'ireheating Awith ythe further advan- "tage that" 'the impedance drop produced by my reactor will be in phase with the transformer counter electromotive force set up bythe excitation current, and is, therefore, more effective than the resistance formerly employed, which produces a drop of 90O from the excitation counter electromotive force of the transformer.

Various changes in detail and arrangey ment maybe made without departing from` the spirit and scope of the invention, as defined by the accompanying claims. For instance, any suitable resistance may be inserted in the auxiliary circuit 8 instead of employingy a portion of t-he reactor as a resistor unit.

I claim as my invention:

1. The combination with a transformer and a. supply circuit therefor, of a main` switch for interrupting the fiow of current to the transformer, ya reactor in shunt relation to the main switch, an auxiliary switch between the reactor and the supply circuit, an auxiliary circuit connected across end turns of the transformer/,and including a portion of the reactor, and a switch for controlling the fiow of current through thek reactor. y

V2. The combination with a transformer and a supply circuit therefor, of a main switch for controlling the supply of current to the transformer, a. reactor connected in shunt relation to themain switch, an auX- iliary circuit connected across end turns of the transformer and including a portion of the reactor therein, and means for making and breaking the auxiliary circuit in predetermined sequence with respect to the operation of the main switch.

3. The combination with a transformer and a supply circuit therefor, of a main switch for controlling the supply of current to the transformer, a reactor connected in shunt relation to the main switch, an auxiliary circuit Vconnected across end turns of the transformer and including a portion of the reactor therein, and means for making and breaking the circuit through the reactor in predetermined sequence with respect to the operation of the main switch.

4. The combination with a. transformer and a supply circuit therefor, of a main switch for controlling the supply of current to the transformer, a reactor connected in shunt relation to the main switch, an auxiliary circuit connected across end turns of the transformer and including a portion of the reactor therein, means for making and breaking the circuit through the reactanee, and means for controlling the auxiliary circuit.

5. The combination with a transformer and a supply circuit therefor, of a switch for controlling the supply of current to the transformer, a shunt circuit around the switch, an impedance in the shunt circuit, and' an auxiliary circuit connected across end turns of thetransformer and including a portion of the impedance therein.

6. The combination with a transformer and a supply circuit therefor, of a main switch for controlling the supply of current to the transformer, a reactor connected in shunt relation to the main switch, an auxiliary circuit connected across end turns of the transformer and including a portion of the reactor therein, means for making and breaking the circuit through the reactance,

and means for controlling the auxiliary circuit, the said two last mentioned means being operable in one predetermined se quence when closing the main switch and in another seque-nce when opening the main switch.

7. The combination with `an clectri al winding and a supply circuit therefor, of a switch for controlling the circuit, an impedance in shunt rela-tion to the switch, and a switch connected across only portions of the said winding and the impedance.`

8. The combination with an electrical winding and a supply circuit therefor, of a switch for controlling the circuit, an impedance in shunt relation to the switch, and an auxiliary circuit that includes only portions of the said winding and impedance.

In testimony whereof, I have hereunto subscribed my name this 2nd day of June, 1922.

LLOYD J. HIBBARD, 

